Monocrystalline Or Polycrystalline Solar Panel

[mat1]

Simple question really, just for the purpose of trickle charging a 100ah battery.

10w Monocrystalline http://www.sunshines...show/SS10W.html

or 15w Polycrystalline http://www.sunshines...how/SSP15P.html ?

Either will be sited in roof light, until I decide, whether or not to roof mount.

The provision is in place for up to 60w (all wired in with charge controller etc), put have no need as always on EHU when away.
I understand the advantages of 60w plus panels, roof mounted etc., but it is purely for trickle charge, battery maintenance in storage.

It would replace http://www.maplin.co...-charger-115194 which has never let the battery go below 12.3v in the past 18 months.

Thanks
Mat

 

[Parksy]

Hi Mat
Monocrystalline solar panels are more efficient than Polycrystalline, but for trickle charging your battery I'd choose the higher output 15w panel.

 

[otherclive]

Mat
how do you connect the small Maplin trickle charger?

 

[mat1]

Mat
how do you connect the small Maplin trickle charger?

I put in a dedicated fused loomed direct to the battery, with 12v socket fitted into the bed box.
That way i could turn all electrics off.
The panel has both cigarette plug or croc clips via ss connector.
I then placed the panel in the roof light.

Mat

 

[mat1]

Have gone with the 15w poly.

Thanks

Mat

 

[GrahamDerby]

Ive just bought a 100w panel and not used it yet but i am away next week and going to see how they perform.
i always used to use a generator but they can be a bit noisy , even the quietest can still get on your nerves. i will let you know how i get on with the panel.

 

[Parksy]

Hi Graham
If you are using it as a freestanding unit which you will connect when setting up on site I'd recommend covering the solar cells or (as I used to) laying the panel on the grass with the cells toward the ground when you do the connecting.
This is to prevent a possible short circuit from damaging the panel if you happened to accidentally short the connectors or connect to the wrong terminal. My mate accidentally let one cable touch the other with the cells charging and the panel had to be replaced.
Have a good trip

 

[mat1]

Sorry for the link to another forum, but i can't upload pictures on here.
Here is my write up following the fitting of the panel.

Mat

 

[Parksy]

Well done Mat

There's no problem with the link, but I put your picture on for you. If you want to know how to upload pictures to this forum have a look at Sprocket's Guide

 

[mat1]

Thanks for that Parksy.
Here is the write up.

Took advantage of the good weather yesterday, to fit the panel.
This is a 15w Polycrystalline that is purely for trickle charge and battery maintenance when in storage.
We are always on EHU when away, so no need for larger.

Same principle used to most, where fixing was concerned, pan head self tapers to fasten the corner mounts to the panel and Sikaflex 252 to fix to the roof.

As you can see i have used the off side awning rail to route the cable, as the battery is on the same side.
Caravan is only a 2010 so plenty of water ingress warranty left, which i didn't want to invalidate.

Due to the size of the panel and cable run distance i decided to go with the cable supplied, 0.75mm2, which is more than capable.
This gives me an acceptable loss of 2%.

A bit of a squeeze but was able to fit the awning rail protector back in place, which was a bonus and helps to protect and hold the cable in place.
As you can see i had to cut the protector where the cable exits the rail, but joined it back again with a cable tie, to hold it all in place.

From the bottom of the rail it was fastened to the underside and fed into the bed box next to the battery, where the charge controller is sat.

The charge controller is connected to the battery using the motor mover power cables, which are heavy duty, fused and a very short run to the battery.

I am very pleased with the outcome.

Mat

 

[mat1]

Dull and cloudy at 8am when i checked the caravan in storage this morning.
Battery voltage at the terminals was 13.12v

Now the caravan has not been used since February and was put away with the battery not fully charged.

Very pleased as the 15w solar panel is doing exactly what i wanted it to do.
Trickle charge and maintain my 100ah battery in storage.

Mat